Nowadays paper or document shredders are widely used, and there are many different models of shredders available on the market for different purposes.
Typically, in conventional document shredders disposed documents are inserted into the shredder through a paper inlet slot normally provided at the top of the shredder casing. The disposed paper or documents are drawn, e.g., by friction rollers or by pushing them down in a given direction and are cut into paper strips by a rotating roller or rollers which consist of a plurality of cutting edges.
In most cases the paper shredders do not have any guiding devices for guiding the paper into the paper input slot, and in many cases after insertion of paper items, especially those that have a length significantly longer than the width, the paper bends back and folds, leading to increase in thickness of the inserted package and resulting in jamming.
In order to prevent canting or bending of long paper items or documents, the user has to hold the trailing end of the paper or paper bundle until the it smoothly passes through the inlet slot to the cutting edges. This is inconvenient and requires additional time for shredding.
To eliminate the above problem, some paper shredders are provided with automatic feeders for automatically feeding the paper items or paper documents one by one to the inlet slot of the shredder.
For example, U.S. Pat. No. 5,662,280 issued in 1997 to T. Nishio, et al. discloses a paper feed device mounted to a shredder. The intermittent activation time of paper feeding is adjusted, taking into consideration the distance from the paper feed start position to the paper shredding position of a cutter of the shredder, thereby decreasing the speed of travel from the time the paper sensor detects the leading edge of the paper to the time the paper reaches the paper shredding position, so that operation is switched from intermittent to continuous activation preferably immediately before the leading edge of the paper reaches the cutter. Thus paper feed troubles associated with conventional devices are prevented, due to paper jamming, etc., caused by bending of the paper, etc.
Devices with automatic feeding of paper are expensive and their use is justifiable only in conjunction with industrially used shredders that operate frequently and in a heavy-duty mode.
U.S. Pat. No. 6,460,790 issued in 2002 to L. Huang discloses a frame width adjusting device for paper shredder. The primary objective of this invention is to provide a paper shredder with a frame width adjusting structure for adjusting the radian of the outer end of the frame such that the paper shredder cooperates with the paper strip collecting containers having openings various in width and shape. In addition, the paper shredder can be held securely in place on the paper strip collecting containers.
However, such a device does not have any guide chutes and is intended for use only with such paper items as paper strips or paper documents having a large length-to-width ratio.